My PS3 is turning itself off after about 20 seconds of being on, even in safe mode. I checked online at Sony's website, and it's going to cost $150 with shipping to send it to them and have them fix it or replace it, money which I do not have right now. It's the old shiny fat 40 GB version, so it's a good 2.5 years old, but my PS2 which is 8 years old still works like a charm, so this kind of depresses me. Anyone have any ideas of what I can do to fix this, or do I just need to wait it out for money and ship it off to Sony?

I had thought of that... I'm not the best at dusting and I looked through the cracks and didn't see any dust, but I'm not really sure how to take it apart. The warranty is already past, so not too worried about voiding it.

a PS3 is essentially a computer, same dust rules apply, same heat issues apply. Since it is no longer warrentied. I'd go buy a can of compressed computer air, open up the case, and blow everything out until there is no more dust. IF that fixes it, great. If it doesn't you have bigger problems and your options are basically try and find a parts donor and replace the power regulator and video modules and hope for luck, or buy a new one. You could possibly just have a dead fan. if so, you can get a replacement unit of the same size from performance-pcs.com.

Question... Is your PS3 suffering YLOD? That's where it'll shutdown with three distinctive beeps followed by a flashing red light. If so I'm afraid your system is good as dead. There are ways to fix YLOD but it's only temporary, usually the fixes are only good enough to transfer your data to a new PS3. Other times it'll last but you're still looking at the inevitable of having to buy a new one. Anyway, it's up to you if you really want to take the risks but here's a site on how to fix YLOD in PS3 systems:

I've used the method listed there twice already to revive my PS3 system, 60GB launch model. I don't frequently use the system anymore so it's sufficient for now at least until I can buy a new system in a few months. So far my current fix has lasted me about 4 months with light to moderate gameplay, usually less than 10 hours per week, 20 if I'm interested in a game. As for opening your system please note that:

* Once the warranty sticker has been voided (It voids the sticker somehow when you try to remove it.) game stores such as GameStop will not take the system and Sony will consider it a modded console and refuse to do repairs to it. This includes just opening it to do a regular cleaning.

If you plan to get a new system later you could always just trade it in somewhere like GameStop. They've got some $200 trade-in deal going on towards PS3 systems. Otherwise you can just send it to Sony. But take note that when you send it to Sony they're going to do a full wipe of your HDD and may even send you a refurbished model or a newer one instead since the fat 40GB models are no longer in production. Well, whatever you decide, good luck.